Mathematics, Statistics & Physics: Recent submissions

Now showing items 401-420 of 740

    • Characterizing the effective reproduction number during the COVID-19 pandemic: Insights from Qatar’s experience 

      Bsat, Raghid; Chemaitelly, Hiam; Coyle, Peter; Tang, Patrick; Hasan, Mohammad R; ... more authors ( International Society of Global Health , 2022 , Article)
      Background: The effective reproduction number, Rt, is a tool to track and understand epidemic dynamics. This investigation of Rt estimations was conducted to guide the national COVID-19 response in Qatar, from the onset ...

    • Goodness-of-fit testing based on Gini Index of spacings for progressively Type-II censored data 

      Pakyari, Reza ( Taylor & Francis , 2021 , Article)
      In this article, we propose two new scale invariant test statistics when the available data are subject to progressively Type-II censoring. The proposed tests are based on Gini index of spacings. It is observed thorough ...

    • On goodness-of-fit testing for Burr type X distribution under progressively type-II censoring 

      Pakyari, Reza; Baklizi, Ayman ( Springer , 2022 , Article)
      In this article, we propose two goodness-of-fit test statistics for the Burr Type X distribution when the available data are subject to progressively Type-II censoring. The proposed test statistics are based on the sample ...

    • Relative infectiousness of SARS-CoV-2 vaccine breakthrough infections, reinfections, and primary infections. 

      Abu-Raddad, Laith J; Chemaitelly, Hiam; Ayoub, Houssein H; Tang, Patrick; Coyle, Peter; ... more authors ( Springer , 2022 , Article)
      SARS-CoV-2 breakthrough infections in vaccinated individuals and in those who had a prior infection have been observed globally, but the transmission potential of these infections is unknown. The RT-qPCR cycle threshold ...

    • A novel method to generate key-dependent s-boxes with identical algebraic properties 

      Ahmad Y., Al-Dweik; Hussain, Iqtadar; Saleh, Moutaz; Mustafa, M.T. ( Elsevier , 2022 , Article)
      The s-box plays the vital role of creating confusion between the ciphertext and secret key in any cryptosystem, and is the only nonlinear component in many block ciphers. Dynamic s-boxes, as compared to static, improve ...

    • Detection of DNA Bases via Field Effect Transistor of Graphene Nanoribbon with a Nanopore: Semi-empirical Modeling 

      Wasfi, Asma; Awwad, Falah; Ayesh, Ahmad I. ( Institute of Electrical and Electronics Engineers , 2021 , Article)
      DNA sequencing techniques are critical in order to investigate genes’ functions. Obtaining fast, accurate, and affordable DNA bases detection makes it possible to acquire personalized medicine. In this article, a ...

    • BNT162b2 and mRNA-1273 COVID-19 vaccine effectiveness against the SARS-CoV-2 Delta variant in Qatar. 

      Tang, Patrick; Hasan, Mohammad R; Chemaitelly, Hiam; Yassine, Hadi M; Benslimane, Fatiha M; ... more authors ( Nature Researc , 2021 , Article)
      With the global expansion of the highly transmissible SARS-CoV-2 Delta (B.1.617.2) variant, we conducted a matched test-negative case-control study to assess the real-world effectiveness of COVID-19 messenger RNA vaccines ...

    • Association of Prior SARS-CoV-2 Infection With Risk of Breakthrough Infection Following mRNA Vaccination in Qatar. 

      Abu-Raddad, Laith J; Chemaitelly, Hiam; Ayoub, Houssein H; Yassine, Hadi M; Benslimane, Fatiha M; ... more authors ( American Medical Association , 2021 , Article)
      The effect of prior SARS-CoV-2 infection on vaccine protection remains poorly understood. To assess protection from SARS-CoV-2 breakthrough infection after mRNA vaccination among persons with vs without prior SARS-CoV-2 ...

    • SARS-CoV-2 antibody-positivity protects against reinfection for at least seven months with 95% efficacy 

      Laith J., Abu-Raddad; Chemaitelly, Hiam; Coyle, Peter; Malek, Joel A.; Ahmed, Ayeda A.; ... more authors ( Elsevier , 2021 , Article)
      Background Reinfection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been documented, raising public health concerns. SARS-CoV-2 reinfections were assessed in a cohort of antibody-positive persons ...

    • mRNA-1273 COVID-19 vaccine effectiveness against the B.1.1.7 and B.1.351 variants and severe COVID-19 disease in Qatar 

      Chemaitelly, Hiam; Yassine, Hadi M.; Benslimane, Fatiha M.; Al Khatib, Hebah A.; Tang, Patrick; ... more authors (2021 , Article)
      The SARS-CoV-2 pandemic continues to be a global health concern. The mRNA-1273 (Moderna) vaccine was reported to have an efficacy of 94.1% at preventing symptomatic COVID-19 due to infection with ‘wild-type’ variants in a ...

    • Epidemiological impact of prioritising SARS-CoV-2 vaccination by antibody status: Mathematical modelling analyses 

      Ayoub, H.H.; Ayoub, Houssein H.; Chemaitelly, Hiam; Makhoul, Monia; Al Kanaani, Zaina; ... more authors ( BMJ Publishing Group , 2021 , Article)
      Background Vaccines against SARS-CoV-2 have been developed, but their availability falls far short of global needs. This study aimed to investigate the impact of prioritising available doses on the basis of recipient ...

    • Bayesian inference for Pr ( Y<X ) in the exponential distribution based on records 

      Baklizi, Ayman ( Elsevier , 2014 , Article)
      We consider Bayesian estimation of the stress–strength reliability based on record values. The estimators are derived under the squared error loss function in the one parameter as well as two-parameter exponential ...

    • New solitary wave and multiple soliton solutions for the time-space coupled fractional mKdV system with time-dependent coefficients 

      Jaradat, H. M; Al-Shara', Safwan; Jaradat, M. M. M; Mustafa, Zead; Alsayyed, O; ... more authors ( American Scientific Publishers , 2016 , Article)
      In this paper, a simplified bilinear method combined with a fractional transform has been used to obtain new multiple soliton solutions for the Fractional coupled modified KdV systems with variable coefficients. These ...

    • Multi-soliton solutions of the BBM equation arisen in shallow water 

      Alsayyed, O.; Jaradat, H. M.; Jaradat, M. M.M.; Mustafa, Zead ( International Scientific Research Publications , 2016 , Article)
      In this work, multiple soliton solutions and multiple singular soliton solutions are formally derived for the BBM equation. A novel transformation method combined with the Hirota's bilinear method are used to determine the ...

    • A new numerical method for heat equation subject to integral specifications 

      Jaradat, H. M.; Jaradat, M. M. M.; Awawdeh, F.; Mustafa, Z.; Alsayyed, O. ( International Scientific Research Publications , 2016 , Article)
      We develop a numerical technique for solving the one-dimensional heat equation that combine classical and integral boundary conditions. The combined Laplace transform, high-precision quadrature schemes, and Stehfest inversion ...

    • Logarithmic Bounds for Oscillatory Singular Integrals on Hardy Spaces 

      Al-Qassem, Hussain; Cheng, Leslie; Pan, Yibiao ( Hindawi Publishing Corporation , 2016 , Article)
      We establish a logarithmic bound for oscillatory singular integrals with quadratic phases on the Hardy space H 1 (R n). The logarithmic rate of growth is the best possible. 2016 Hussain Al-Qassem et al.

    • Selective hydrogen gas sensor using CuFe 2 O 4 nanoparticle based thin film 

      Haija, Mohammad Abu; Ayesh, Ahmad I.; Ahmed, Sadiqa; Katsiotis, Marios S. ( Elsevier B.V. , 2016 , Article)
      Hydrogen gas sensors based on CuFe2O4 nanoparticle thin films are presented in this work. Each gas sensor was prepared by depositing CuFe2O4 thin film on a glass substrate by dc sputtering inside a high vacuum chamber. ...

    • An algorithm approach to maximal monotone operators and pseudo-contractions 

      Zhu, Xinhe; Yao, Zhangsong; Hamdi, Abdelouahed ( International Scientific Research Publications , 2016 , Article)
      The purpose of this article is to find the minimum norm solution of maximal monotone operators and strict pseudo-contractions in Hilbert spaces. A parallel algorithm is constructed. Some analysis techniques are used to ...

    • Bioinformatic analysis of human opn3 alternative promoters associated with cancer 

      Ibrahim Al-Obaide, Mohammed A.; Abdel-Salam, Abdel Salam G.; Alobydi, Hytham; Srivenugopal, Kalkunte S. ( Natural Sciences Publishing Co. , 2016 , Article)
      In this bioinformatics study we analyzed the functional motifs and structural features of regulatory regions of OPN3, a member of the guanine nucleotide-binding protein (G protein)-coupled receptor super-family, which is ...

    • Enhancing passive UHF RFID backscatter energy using chirp spread spectrum signals and channel shortening 

      Ben-Jabeur, Taoufik; Kadri, Abdullah; Hazaa, Khalifa Abdulla ( Institute of Electrical and Electronics Engineers Inc. , 2016 , Conference Paper)
      Performance of passive ultrahigh frequency radio-frequency identification (UHF RFID) systems depends on the energy level of the backscattered signal from the RF tag to the RFID reader. In the indoor environment, the ...